Electrically-heated device



Dec. 26, 1922.

E. H. RICHARDSON. ELECTRICALLY HEATED DEVICE.

2 SHEETS-SHEET I;

HLED FEB. 21,1921.

Figl.

.7 (ilk-1.2 10' a 2/ /6 Fig. 2.

Inventor: Earl H.Richav-d son a! E.

His Attornea.

Dec. 26, 1922. 1,439,979. E. H. RICHARDSON.

ELECTRICALLY HEATED DEVICE.

FILED FEB. 21, I92]. 2 SHEETS*SHEET 2.

Inventor: Earl H.Richa-r-dson,

Hiskbtornes.

in is a specification.

seamed Dec. 26, 1922;

UNITED STATES PATENT OFFICE.

EARL H. RICHARDSON, OF ONTARIO, CALIFORNIA, ASSIGNOR TO EDISON ELECTRIC APPLIANCE COMPANY, INC., A

CORPORATION OF NEW YOBIL.

ELECTRICALLY-HEATED DEVICE.

pplication filed February 21, 1921. Serial No. 446,618.

To'aZZ whom it mag/0011mm:

Be it known that I, EARL H. RICHARDSON, a citizen of the United States, residing at Ontario, in the county of San Bernardino, State of California, have invented certain new. and useful Improvements in Electrically-Heated Devices, of which the followy invention relates to electrically heated devices and more particularly to means for rotecting such devices from overheating.

fy improved arrangement is particularly applicable to electrically heated fiat irons, a though it is not necessarily limited to this application.

In carrying out my pfesent invention, I employ the ratchet or toothed-wheel arrangement disclosed in my previous Patent No. 937,332, dated Oct. 19, 1909. In the arrangement of said patent the ratchet wheel is normally held stationary by a fusible metal which melts at the temperature at which the device is to operate and .allows the ratchet wheel to turn and open tion .is the provision of a simple and eflicient arrangement cooperatingwith thenormally stationary ratchet wheel whereby, when a predetermined temperature is reached, the circuit is opened with a quick break action, and when the flat iron or other electrically heated device cools off sufficiently, the switch may be closed manu ally with a snap action. The arrangement is such that the parts, including the spring which causes the snap action, are unaffected by the temperature at which the device is operated. I have also provided -a fusible metal which is practically free from oxidation due to repeated melting and so lidifying. This improved fusible metal, which is in fact an alloy, forms an important part of my present invention.

In the accompanying drawings illustratin one embodiment of my invention, Fig.

V1- is a side elevation of a flat iron incorplan view with the cover removed to show the switch mechanism; Fig. 3 shows an enlarged view of the, switch mechanism; Fig.

4 is a detail of the contact member of the switch, and Fig. 5 is a plan view of the same.

Referring to the drawings it will be seen that I have shown my invention in connectogether by the screw 13. The cover 14 has an enlargement at 15 to take care of the added depth required by the switch mechanism. The numeral 16 indicates a well formed in the sole plate for containing the fusible metal or alloy 17. A vertical shaft 18, having its lower bearing in the bottom of the well at 19, extends upward through an opening in the plate 11 and is provided at its upper end with a toothed or ratchet wheel 20 rigidly fastened to theshaft. The lower end of the shaft which is embedded in the fusible metal is provided with anchoring projections 21.

The switch mechanism cooperating with the ratchet wheel 20 is clearly illustrated in Fig. 3. 1 It consists of a supporting plate 22, upon which is mounted a stationary bracket consisting of a flanged base 23 secured to the plate 22" and the two outwardly projecting wing portions 24 and 25 which are above and spaced from the plate 22. Pivotdicated indetail in Figs. 4 and 5, in which 'the bridging member 26' which cooperates with stationary -contacts 2.7 is shown mounted on member 26 so as to be insulated therefrom, through the agency of a clamp 28 having a loop portion which looseliy supports member 26' to allow for self a justment of the contacts when the switch is closed. The operating member for the switch is indicated by the numeral 28. This j member is channel-shaped, as shown, and

underneath it in the plate 22.

1 ter-clockwise has at one end aknife-edge bearing at 29 in wing 24 and a similar bearin directly end of this member is provided with a hook 30 which is connected by a. link 31 with an S-shaped member 32. This link 31 is Z- shaped and pivoted to hook 30 on cars 31', the lower portion forming a pawl 29' as shown. The lower end of the S=shaped member is connected with theswitch member '26 by a link 33, while the upper end-is connected with a spring 34 by a. link 35. This spring, which is of ample proportions and contains several coils, is adjustably secured to theplate 22 by being mounted in lugs 22' on a rotatable plate 23 of the form shown in dotted lines, the lugs projecting through slots in plate 22. This plate 23'. is provided with upwardly projecting lugs 36 which embrace the cam shaped edge37 of the plate 22. This rotatable plate is provided with a projection 38 for turningthe plate and thereby turning the end of the spring to change the tension. .The outline of the portion 37 of the plate 22 is cam.

shaped so that when the plate is placed in the proper position by the projection 38 tothe spring extends to the right and engages a slot in the link 35, which link passes through a slot in the link 33 and also through a slot in the meinber 28. Looking at Fig. 3 therefore, the spring pulls down on the-link 35 thereby giving the S-shaped member 32 a tendency to rotate in a coundirection. This, therefore, gives the link 33 a tendency to moveto the right. When, therefore, the point of support 33' for the link 33 is above the knife edge, 27, the spring, acting through the yS shaped member 32 and link 33, will force 33 passes, below the knife edge 27, the switch member may be forced downward to open position. This gives a snap action in both directions, as-will be well understood. The pawl 29"forming a part of link 31 and engaglng the teethof the ratchet wheel .20, 1s, ratchet teeth by the spring 34. since the link 31, which is in one piece with the pawl, is forced downward by the spring through the link 35. An operating knob or button 39. is PIVOtBd' to the operating member 28 at 40 so as to have a slight motion to adjust itself in I its various positions. A stop 41 limits the downward movement of the operating member 28. This button 39 projects '65 -tomatically opened, the button projects out- Theother therefore, forced inward against the contacts are not bridged by the member :26

thecircuit to the heating element will/be 0 en. 1 j

The fusiblealloy "17 employedin the well 16 is one which I have found in practice to be practically non-oxidizable. One of the principal difliculties met ,wit-hlj in devices depending upon a fusible metal for their action is that the metal, in time, will oxidize due to repeated melting and solidifying and will become ineffective. I'have produced an alloy, however, in which oxidization does not occur, at least within practical limits. The

- alloy wh-ioh I have found to be very serviceable is composed of 90% zinc, 4% bismuth and 6% aluminum, and I have found that these -me'tals should be as nearly pure as possible in order to obtain the best results.

The melting point of this alloy is about 750 FI, and is practically constant in the transition from the solid to the liquid state, and vice versa. Its characteristics do not change after repeated melting and solidifymg.

As thus constructed and arranged the operation of my device is as follows: I

In Fig.2 the parts are in thejposition in which they are left when the switch has antomatically opened. Assuming that the iron has cooled off sufficiently so that'the fusible metal has solidified, the ratchet wheel 20 will be held stationary. In order to close the switch now, the operator pushes on the button 39 which projects through the casing 15, until the end is practically flush with the casing. In doing this the pawl 29 passes over the teeth of the ratchet 20 as the member 28 is moved inward. As this member 28 moves inward, carrying *with it the S-shaped member 32 and the links attached thereto, the link 33 passes above the knife edge 27 so that the pull on the link 33 will now cause a turning movement of the switch member 26 around the knife edge 27 to close the switch. The switch will therefore close to the position shown in Fig. 3 with a snap action and the pawl 29 engaging with the I teeth of the ratchet 20'will hold it in this position. Assuming now that the iron is in operation and that it reaches a temperature of approximately 750 F., the'fusible alloy 17 in the well 16 will melt, thereby allowing the shaft 18 carrying the ratchet wheel 20 to turn. Since the wheel 20 no longer holds the switch parts in place, since it will turn under the tensionof the spring on the switch parts, the latterwill be carried back to the position shown in Fig. 2. As soon as the link 33 passes below the knife edge vention as embodied in concrete form and as operating in a specific manner in accordance with-the provisions of the patent statutes, it should be understood that I do not limit my invention thereto, since various modifications thereof will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is set forth in the annexed claims.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. An electrically heated flat iron comprising a' switch for making and breaking the heating circuit, an operating member therefor biased to the open position of said switch, connections between the member and said switch whereby a quick make and break action of the switch is effected by the movement of the member in opposite directions,

means for manually moving the member against its bias to a position to close the switch, and means for holding the member insuch position when the temperature .is below a predetermined value but releasing it when the temperature rises to said value.

*2. An electrically heated fiat iron comprising a switch for making and breaking the heating circuit, an operating'membertherefor biased to the open position of said switch,

connections between the member and said switch whereby a quick make and break action of the switch is effected by the movement of the member in opposite directions, and a rotatable element held stationary when the" temperature is below a predetermined value arranged to hold the member in closed position, said element being released to effeet the opening of thev switch 'when the temperature rises to said value. 3. An electrically heated fiat iron comprisin a quick nake and break switch in the heating circuit, and an element held sta tionary when the temperature is below. a

predetermined value for holding the switch in closed position but released to effect the. opening of the switch when the temperature rises to said v'alue.

" 4, An electrically heated flat'iron 'comprising a quick make and. break switch in; the

heating-circuit, an operating member therefor manually operated to the closed position of said switch and biased to the open position thereof, and an element/held stationary when the temperature-is below a predeterclosed position against its. bias and releasing it to effect the opening of the switch when the temperature rises to said value.

An electrically heated fiat iron com-' prising a switch operating member biased to one position, manually operated means for holding the member against the bias to a second position, a quick make and break switch operated-to open and closed positions by the movement of said member, and a rotary element for holding the member in closed position when the temperature is below a predeterminedvalue and releasing it to open the switch when the temperature rises to said value.

heating circuit, an operating member therefor biased to the openposition of said switch,

so 6. An electrically heated flat iron compris inga switch; for making and breaking the tion of the switch is effected. by the movement of the member in the opposite directions, a rotatable element held stationary when the temperature is below a predetermined value arranged to hold the member in closed position, said element being released to effect the opening of the switch when the temperature rises to said value, a cover for said switch hanism and a member secured to the switc operating member and projecting through the cover for manuallyclosing the switch when said member is pressed intothe cover.

7 5 An electrically heated fiat iron comprising a quick make and break switch in the heating circuit, a rotary element for holding the switch in closed position and a fusible metal fo r holding the rotary element stationary when the temperature-is below a pre-' determined value but releasing it to effect the opening of the switch when the temperature rises to said value. v

8. An electrically heated flat iron comprisi ing a quick make and break switclr in the heating circuit, arotary element for holding the switch in closed position and an inoxv idizable fusible metal for holding the rotary element stationary when the temperature is below a predetermined value but r eleasing itto, effect the opening of the switch when the temperature rises to said value.

9. Ani electricall yf heated flat iron comprising a quick make'an'd break switch in the heating circuit, a rotary element for holding the switch in the closed position and an inoxidizable fusible alloy having a base of a low fusing point metal and asmall con- 1 tent of aluminum forholding the rotary element stationary when the temperature is below a predetermined value but releasing it to effect the opening of the switch when the temperature rises to said value. p v '10. An elegtricall' heated flatiron com-v mined value for holding the member infprising a quickmake and break switch: in 1:0

the heating circuit, a rotary element for holding the switch in the closed position and an inoxidizable fusible alloy containing at least 75% zinc and approximately 5% aluminum for holding the rotary element stationary when the temperature is below a predetermined value but releasinigl it to effect the opening of the. switch when e temperature rises tosaid' value? 11. An electrically heated flat iron comprising a quick make'and break switch in the heating circuit,'a rotary element-for holdthe temperature is below a predetermined value but releasing it to efi'ect the opening of the switch when said value.

In'witness whereof, I have hereunto set my hand this ninth day of February, 1921.

EARL RICHARDSON.

the temperature rises to 

